Thomas carr



UNITED STATES PATENT OFFICE.

THOMAS CARR, OF LIVERPOOL, ENGLAND.

STEERING APPARATUS FOR SHIPS.

Specification of Letters Patent No. 16,045, dated November 11, 1856.

To all whom it may concern:

Be it known that I, THOMAS CARR, 01 Liverpool, in that part of the United Kingdom of Great Britain and Ireland called England, have invented a new and useful Machine or Apparatus for Steering Vessels, being an improvement of an invention of mine for which I obtained Letters Patent for Great Britain, dated August 28, 1854; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings and the letters and figures marked thereon, making a part of this specification, in which Figure 1, is a partial sectional side elevation, and Fig. 2, is plan view of the improved steering apparatus.

Fig. 1, shows the apparatus in the position it would be when the rudder and tiller are in aline with the keel, or amidships, and Fig. 2, shows it hard over to one side.

The novelty of the invention may be briefly stated to consist in the addition to the ordinary steering apparatus, of either an eccentric, or, its equivalent, a crank, (as shown in the drawings) working in combination with an entire pulley or its segment, a quadrant, on a vertical axis, the whole being interposed, as a medium of connection, between the ropes or chains and the tiller.

To construct an apparatus according to one of the modifications of my invention, I use the steering wheel, axle, rope barrel, and the two small side pulleys of the ordinary steering apparatus, but instead of the ropes which pass through little pulleys being carried direct to the tiller as they usually are, they are made fast to a large horizontal pulley, after being wound partly around the grooves on its edge. This horizontal pulley (which is from three to four feet diameter) turns freely on a vertical axis, or stud, on the center of the deck, a short distance abaft the rudder head. Near the periphery of the large horizontal pulley at a part cast solid for the purpose, a vertical crank pin is secured, which is connected to a longitudinal slotted tiller, by passing up through a slid ing block, which works freely within the longitudinal slot formed in the center of the tiller, or the tiller may be formed without the longitudinal slot shown in the annexed drawings, as it can be formed of a solid bar and work through an eye formed on, or at tached to, the head of the vertical pin to which it is connected and receives motion from the large horizontal pulley in the way shown by the drawing which accompanies this specification.

It will be seen on reference to the annexed drawings, that the steering wheel, axle and rope barrel of the ordinary steering apparatus, are retained, but instead of the ropes, which pass through the little pulleys G. G, being applied at once to the tiller, as they usually are, are made fast instead to the large horizontal pulley E, after being wound partly around the groove on its edge. The pulley E, turns freely on its vertical axis, or stud, B, on which it is secured from rising by a cap or lid, which-is bolted down to the axis. The axis itself has a flange on its base, by which it is secured to the center of the deck a short distance abaft the rudder head L. Near the periphery of the pulley E, at a part cast solid for the purpose, the vertical pin A, is secured, which is connected to the slotted tiller K, by passing up through a sliding block which works freely in its slot. Thus, it will be seen, when the steering wheel is turned, the ropes acting on the pul ley E, cause it partially to revolve, and in doing so to traverse the tiller K, by the pin A, sliding down its slot, till the tiller has attained its utmost travel of 45 and the pin at the same time the termination of the slot, by which time it is so arranged that a radius line passing through the center of the axis and pin should have become nearly at right angles to the tiller, or in other words that the apparatus should have come almost on its dead center with the tiller, as shown in the planview of the drawings. Now the obvious result of this is that when the rudder is hard over, where it is usually most dilficult and dangerous to hold, it becomes in a great measure deprived of its tendency to revolve the pulley, (and consequently the steering wheel) and furthermore that for very many degrees before it reaches that position, its force becomes directed so much toward the center of motion of the pulley, that the friction of the large axis and other working parts, its sufficient, under such circumstances, to so soften down and neutralize its violence, as to render necessary only the most trivial exertion on the part of the man to hold the helm where required.

The apparatus when hard overcomes almost on its dead center with the tiller, for

though, as it is shown in the plan drawing, it can as easily be made to do so entirely and thus bring the tiller as it were to a dead lock, yet I consider it not advisable to do so, in order that the tiller may never be held perfectly rigid, but may have a slight tendency left it even at its greatest angle to revolve the pulley and so break the abruptness of heavy shocks, by gently yielding to them. Thus it forms an exact medium between the unadvisable rigidity of the screw and the dangerous freedom of the ordinary appartus. But though the power of the sea, so far as it might be dangerous, is thus so effectually neutralized, the very reverse is the case with that of the man, for acting, as it does by the ropes, at a perpetual tangent to the pulley, its tendency to revolve the latter not only remains perfect throughout, but an actual increase of power is continually effected the farther the helm is brought over, notwithstanding the apparent loss observable in the diminishing length of the tiller, as the pin slides down it. This increasing leverage, is due to the indirect action of the pin on the tiller, occasioned by its sliding down the tiller as well as forcing it out. I say indirect act-ion, for though the pin can not stir without moving the tiller, yet the former in doing so traverses over three times the number of degrees the latter does, the total travel of the tiller being limited as usual to one quarter of a circle, while that of the pin is nearly three quarters of one. How this causes the leverage to be one of continuous increase will be more readily understood on considering either the working of the model or plan view of the annexed drawings, for in doing so, it will be observed that it is only when the tiller is amidships that its speed and direction exactly coincide with that of the pin and that the nearer the tiller approaches the extremity of its travel its motion becomes slower and slower in proportion to the speed of the pin itself, pulley and steering wheel, so much slower indeed does it at length become, that two or three times the number of wheel spokes must pass through the mans hand to move the rudder its last ten clegrees, say from 35 to 45, than were sufficient when amidships to move it in the first ten, and consequently from the principle of mechanics it is evident that the power must necessarily increase in the same proportion as the relative speed of the tiller diminishes. In short the farther the helm is brought over the action of the pin assumes more and more the principle of an inclined plane, wedging up, as it were, the tiller against the sea with slow, but resistless power. Thus the diminishing leverage observable in the shortening tiller, is more than doubly compensated for by the more rapidly increasing purchase of the pulley its crank pin approaches toward its dead center with the tiller.

The two small side pulleys through which the tiller ropes or chains pass to the large horizontal pulley may be so fitted that they can be drawn farther apart from each other for the purpose of tightening the tiller ropes or chains when required.

It will be evident, that in place of the crank motion above described a modification of it commonly termed an eccentric may be employed, as the action of the two is precisely the same, the eccentric being only a crank with its pin enlarged sufficiently to embrace its axis of rotation.

in combination with an entire pulley or its segment or quadrant on a vertical axis the whole being interposed as a medium of communication between the wheel ropes or chains and the tiller.

In witness whereof I the said TI-IOMAS' CARR, have hereunto set my hand and seal this fifteenth day of August in the year of our Lord one thousand eight hundred and fifty-six.

THOMAS oxen L 8.

Signed and sealed in the presence of WILLIAM WALKER, JOHN CoNwAY. 

